ISPs require to exercise a very fine control over the traffic carried by their networks in order to support QoS related to various of these traffic flows. One of the ways to assess network load is by analyzing the traffic flows through the network and this assessment would in turn help manage SLAs. Another use of the network analysis is to help in network capacity planning by assessing the load due to each of the network protocols. A typical network traffic is based on a standard protocol and the knowledge of the protocol is quite adequate to determine the traffic based on that protocol. In this case, the header analysis and state machine based analysis would help determine the traffic related to the various standard based protocols. On the other hand, there are a handful of protocols that are proprietary based and unless update information about these protocols is made available by proprietary protocol owners, it becomes a big challenge to determine the flows related to these protocols. However, it is very important for ISPs to know about these protocols as well. In many cases, such protocols could be discovered by careful analysis of the various protocol states. Hence, it is required for the protocol header to be available in plain form for analysis. In case the proprietary protocol header/payload gets encrypted, it becomes a bigger challenge to determine the same. It is very useful to device techniques that can help identify such encrypted proprietary protocols.